The inspection of a new or worn tire can be useful for investigating one or more aspects of its condition. Such an inspection may explore e.g., surface features of the tire or internal features that are normally hidden from view. Frequently, conducting the inspection without damaging or deconstructing the tire is desirable. Where internal features are to be inspected, the use of one or more specially designed devices is typically necessary.
By way of example, a known tire construction uses a body ply having reinforcement elements that extend from bead portion to bead portion through opposing sidewall portions, and a crown portion of the tire. Sometimes referred to as the carcass ply or reinforcing ply, the body ply is typically anchored at the beads and maintains the overall shape of the tire as the tire is inflated and used. The reinforcement elements of the body ply are usually oriented substantially along the radial direction (a direction perpendicular to the axis of rotation) and can include e.g., a ferrous metal.
During use of the tire, these reinforcement elements (sometimes referred to as cords) may be damaged e.g., from impact with objects in the roadway, travel over curbs, and other damaging events. Fatigue of the reinforcement elements as result of continued use at high loads and/or low air pressure can also occur. In some situations, the reinforcement elements may be completely broken as a result of such events. Unfortunately, this damage may not be readily discoverable from a visual inspection of the exterior of the tire because the reinforcement elements are contained within the rubber materials used to construct the tire.
Commercial tires are commonly reused after a process referred to as retreading. With retreading, worn tread is removed from the tire and a new tread belt or tread section is installed onto the tire. Replacement of the tread is less expensive than replacing the whole tire and allows additional mileage to be obtained using the same tire carcass. This practice is common particularly with commercial tires for heavy trucks. Before replacing the tread, however, it is advantageous to inspect the tire, including the internal reinforcement elements of the body ply, for damage or wear. In certain situations, inspection may reveal that replacement of the tire is required rather than retreading. Alternatively, repair of the tire may be required. By way of example, specially designed optical instruments may be used to inspect external or surface features. However, as stated above, not all damage to interior elements such as e.g., the reinforcement elements of the body ply are readily apparent from a visual inspection alone.
Whether investigating external features or internal features such as e.g., the reinforcement elements, automation of the tire inspection process is very desirable so that multiple tires may be inspected economically and expediently. Challenges face such automation because tires come in a variety of shapes and sizes. More specifically, the profile, height, and width (along the axial direction) can vary substantially from tire to tire. For tire inspection, some sensors require placement at close proximity to the surface of the tire. For example, placement of one or more sensors near an inner surface of the tire either in contact with the tire or in close proximity thereto may be required. Automating such a process can be problematic with tire profile and size changes from tire to tire.
Furthermore, increased complexities can be encountered in the detection of discontinuities at certain locations of the tire. The repeatable and proper placement of such sensors along e.g., the shoulder portion of the tire at the inner surface can be particularly challenging because of the curvature at the shoulder portion and the variability of the curvature between tires of different sizes and types. Similarly, repeatable and proper placement of such sensors near the bead portion can also be challenging.
Accordingly, a device that can be repeatably and properly positioned for tire inspection would be useful. More particularly, a device for tire inspection that can be placed near or in contact with the surface of the tire and at different locations would be beneficial. Such a device that can detect whether it is in proper proximity relative to the tire or a surface of the tire such that one or more tire inspections sensors can properly operate would also be useful. Such a device that can be repeatably and properly positioned for the inspection of multiple tires having different sizes or profiles would be particularly beneficial.